Day: October 13, 2013

[James] wanted to build a BEAM turbot. He ran into some problems with the BEAM circuitry though, and ended up with a BEAM/Picaxe hybrid.Beam robotics are the brainchild of Mark Tilden. The acronym stands for Biology, Electronics, Aesthetics, and Mechanics. BEAM based bots were very popular with hobbyists in the 90’s and early 2000’s, but popularity has since died down. BEAM robots tend not to use microcontrollers, instead attempting to simplify things down to the lowest number of elements.

[James’] turbot uses a miller solar engine. The original design used the engine to drive a Solar Turbot Latch. [James’] problem was that the photodiode “eyes” of the robot were not properly enabling the 74AC245 to pass current to the motor. Since the robot was built in a tiny space, debugging the circuit was extremely hard. After struggling with the ‘245 for some time, [James] decided to swich out the BEAM circuit for a Picaxe microcontroller.

The Picaxe can only sink or source about 20ma per pin, which is slightly less than the no load current of [James’] motors. To make up for this, he ganged up four pins per motor. There was some risk in the motors blowing up the Picaxe. However between the lightly loaded gearmotors and low current solar panels it seems to be working just fine. Overall the bot is a very clean, compact build. Jump past the break to check out its really smooth crablike walking action.

The Hackaday tips line is always full of the coolest completed projects, but only rarely do we see people reaching out for help on their latest build. We’ll help when we can, but [Tim]’s relay-based CPU has us stumped.

[Tim] already has the design of his relay CPU completed with a 12-bit program counter, sequencer, ALU, and a transistor-based ROM. The problem he’s having deals with the mechanics and layout of his homebuilt CPU. Right now, all the relays (PC pin, we guess) are glued top-down to a piece of cardboard. This allows him to easily solder the wires up and change out the inevitable mistakes. This comes with a drawback, though: he’s dealing with a lot of ‘cable salad’ and it’s not exactly the prettiest project ever.

The ideal solution, [Tim] says, would be a PCB with through-hole plating, but this isn’t easy or cheap for the home fab lab. We’d suggest some sort of wire wrap setup, but proper wire wrap sockets and protoboards are for some reason unreasonably expensive.

If you have an idea on how to do the mechanical layout and connections of a relay-based computer, drop a note in the comments. [Tim] has a very cool project here, and it would be a shame if he were to give up on it due to a lack of tools.

Video below, and if you’re having a problem with a project, feel free to send it in.

Some of the most inefficient appliances in the home are AC mains-powered clocks. You can’t exactly turn them off and they use a whole lot of energy considering how often they’re looked at. [t3andy] came up with a great low power AC Mains clock that is only on 3% of the time. As a neat bonus, it also looks really, really cool.

[t3andy] is using a Teensy 3 as the brains of this clock, and the serial interface on the board provides a relatively easy means of setting the time without having to use buttons or tact switches. The clock face consists of 13 neopixels, with two red pixels showing the hour and a single green pixel showing the minutes. The time is measured with a DS3232 I2C real time clock with a battery backup.

The design is remarkably efficient since the LEDs are off 97% of the time, only being lit at the top of the minute. There are provisions for IR control and a PIR sensor to display the time whenever it’s needed, but that would obviously mean a hit to the energy efficiency.

[ElectricSlim] likes taking “Jump Shots” – photographs where the subject is captured in midair. He’s created a novel method to catch the perfect moment with OpenCV and Processing. Anyone who has tried jump shot photography can tell you how frustrating it is. Even with an experienced photographer at the shutter, shots are as likely to miss that perfect moment as they are to catch it. This is even harder when you’re trying to take jump shots solo. Wireless shutter releases can work, but unless you have a DSLR, shutter lag can cause you to miss the mark.

[ElectricSlim] decided to put his programming skills to work on the problem. He wrote a Processing sketch using the OpenCV library. The sketch has a relatively simple logic path: “IF a face is detected within a bounding box AND the face is dropping in height THEN snap a picture” The system isn’t perfect, A person must be looking directly at the camera for the photo the face to be detected. However, it’s good enough to take some great shots. The software is also repeatable enough to make animations of various jump shots, as seen in [ElectricSlim’s] video.

We think this would be a great starting point for a trigger system. Use a webcam to determine when to shoot a picture. When the conditions pass, a trigger could be sent to a DSLR, resulting in a much higher quality frame than what most webcams can produce.

Home automation keeps popping up here at Hackaday, so [Cristian Zatonyl] decided to share his Raspberry Pi-based system with us. This build takes a firm stance on the “automated” side of the automation vs. control debate we had last week: no user input necessary. Instead, [Cristian] relies on geofencing to detect whether he has driven outside the set radius and automatically turns off the lights and locks his door.

The build takes advantage of Z-Wave products, which are your typical wireless remote-control gadgets, but tacks on a third-party “RaZberry” board to a Raspi to give it control over off-the-shelf Z-wave devices. The final step is the integration of a custom iOS app that keeps tabs on the geofence boundaries and signals the Pi to control the lights and the front door lock.

[Cristian’s] tutorial covers the basics and admits that it’s a proof of concept without any security features. Judging by his other YouTube videos, however, we’re sure more developments are underway. Check out the video below for a demonstration of the system, then feel free to speculate on security concerns in the comments. Our article on Z-wave security from a few years ago might be a good starting point.

We throw away millions of tons of e-waste every year and barely manage to recycle more than 15-20%. [Kodjo Afate Gnikou] is a 33-year old African who has just finished off a 3D printer built almost entirely out of e-waste.

He started the project months ago on Ulule, a European crowdfunding site, and had raised more than €4,000 to develop the idea. It was designed and built in WoeLab, which is the first hackerspace in western Africa. The printer is based on the classic Prusa Mendel, which they had available in the hackerspace.

The goal of the project was to create a 3D printer that is very easy to reproduce using a majority of recycled components. In the end, they succeeded and it only cost $100 to manufacture — while it doesn’t say what the purchased components are, it’s safe to assume they would have to be the main driver boards — everything else could have been made from scraps.